Parental precaution: Neurobiological means and adaptive ends

Abstract

Humans invest precious reproductive resources in just a few offspring, who remain vulnerable for an extended period of their lifetimes relative to other primates. Therefore, it is likely that humans evolved a rich precautionary psychology that assists in the formidable task of protecting offspring. In this review, we integrate precautionary behaviors during pregnancy and postpartum with the adaptive functions they may serve and what is known of their biological mediators, particularly brain systems motivating security and attachment. We highlight the role of reproductive hormones in (i) priming parental affiliation with young to incentivize offspring protection, (ii) focusing parental attention on cues of potential threat, and (iii) facilitating maternal defense against potentially dangerous conspecifics and predators. Throughout, we center discussion on adaptive responses to threats of disease, accident and assault as common causes of child mortality in the ancestral past.

Maternal Defense

“…Further research is needed to assess the impact of the proximity of infants to ostensibly hostile persons on human maternal defense. In addition, contextual factors such as the sex or relative formidability of the hostile persons, or the quality of mother-infant attachment, may influence maternal defense (Hahn-Holbrook et al, 2011). …”

Human threat management systems: Self-protection and disease avoidance

“…This adaptive flexibility is evident in context-contingent variability in the tendency for prototypically disgusting stimuli to actually elicit disgust. For example, women show more exaggerated disgust responses during the first trimester of pregnancy—a time in which their body’s natural immunological defenses are temporarily suppressed (Fessler, Eng, & Navarrete, 2005; see Hahn-Holbrook, Holbrook, & Haselton, 2010, this issue, and Lienard, 2010, this issue, for reviews of these and related findings). Perceived vulnerability to disease also influences behavioral responses to social cues that heuristically connote pathogen infection.…”

“…Nonetheless, these biases can cause problems in the here-and-now. Recent work, for instance, suggests that an extreme lowering of thresholds for identifying cues and events as threats, or a difficulty “turning off” precautionary systems, may contribute to psychological disorders such as post-traumatic stress disorder (linked to the self-protection system), some forms of obsessive-compulsive disorder (e.g., hand-washing, linked to the disease-avoidance system, and post-partum obsessive-compulsive disorder, linked to aspects of the kin-care system), social anxiety disorder (linked to the social affiliation system), and the like (e.g., Boyer & Lienard, 2008; Eilam et al, 2010, this issue; Hahn-Holbrook et al, 2010, this issue; Szechtman & Woody, 2004; Woody & Szechtman, 2010, this issue). …”

Individual differences in activation of the parental care motivational system: Assessment, prediction, and implications.

“…The parental care system appears to be activated by perceptual cues and inferential events connoting the immediate need to provide care for offspring. This is evident in research documenting the consequences of becoming a parent: Many phys iological (e.g., hormonal) changes accompany parenthood, and these changes are linked to social-bonding and/or protective re sponses that serve the objective of parental care (e.g., Atzil, Hendler, & Feldman, 2011;Edelstein, Stanton, Henderson, & Sanders, 2010;Gordon, Zagoory-Sharon, Leckman, & Feldman, 2010;Hahn-Holbrook, Holbrook, & Haselton, 2011;Hume & Wynne-Edwards, 2005;Leuner, Glasper, & Gould, 2010). In women, some of these physiological changes may be directly tied to pregnancy, childbirth, and lactation.…”